Partially cook bacon 3 minutes in a nonstick skillet; drain and set aside.

In a food processor combine finely chopped onion, cheese, yogurt and pepper; process until onion is minced. Set aside.

Place toasted bread slices on a baking sheet. Spread cheese mixture evenly over slices, spreading to edges of bread. Cut tomato into 4 slices. Top each bread slice with a tomato slice and 2 bacon pieces. Broil 2 to 2 1/2 minutes or until cheese melts and bacon is crisp. Sprinkle with green onions.